Rifle Sights

A manufacturer of after-market Tactical Rifle Sights had been manually assembling a folding rear sight. The sight contained two Solid Dowel Pins, and a Slotted Spring Pin. The Solid Pins were manually installed in a multistage process. Due to manufacturing tolerances, the pins were occasionally loose, requiring an additional operation to ensure retention. The Slotted Pin was also manually installed. This process required the operator to pre-compress a spring with a clamp, then "start" the Slotted Pin into the hole. The sub-assembly was then placed under a manual press to complete the installation. The pin was not easy to handle due to its small diameter resulting in a slow, tedious process. Any misalignment of the pin resulted in damage to the assembly, therefore alignment and proper pin location was critical.
app coiled pin solid pin automation rifle site
Rifle Sight
app coiled pin solid pin automation rifle site fixture
Coiled Pin, Helical Grooved Pins, and fixture for the Coiled Pin installation.
model pr model crd
Model PR for the Coiled Pin installation, Model CRD for the simultaneous installation of the two Helical Grooved Pins (shown without guard).
SPIROL engineers recommended the use of Helical Grooved Pins in place of the Solid Dowel Pins to absorb hole tolerances and provide positive retention, and a Model CRD Automatic Dual Pin Insertion Machine to install the pins. The operator easily loads the sight into a fixture nest, and activates the machine. The inserter advances, simultaneously installs both Helical Grooved Pins, retracts and resets. This machine/pin combo has improved production four-fold, and virtually eliminated all scrap.

The customer also replaced the Slotted Pin with an automation-friendly Coiled Spring Pin and uses a Model PR Automatic Pin Inserter with a custom designed fixture to ensure trouble free pin installation. The operator simply places the assembly into the fixture, locates the fixture onto a post, and then gently pushes the assembly forward to compress the spring. The assembly then moves over an alignment pin, and the machine is activated to automatically install the Coiled Pin.

Our staff of engineers will review your application needs and work with your design team to recommend the best solution.

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SPIROL offers complimentary Application Engineering support. We will assist on new designs as well as help resolve issues, and recommend cost savings on existing designs.